> because you can't make asciinema span multiple tabs or panes

Of course you can:

1. create tmux session, create splits/panes 2. detach 3. asciinema rec 4. attach (inside asciinema rec)

This way asciinema records your whole terminal, and tmux running inside of it.

In other words, if you have it like this:

terminal -> tmux -> pane -> asciinema rec

asciinema can't see outside of the pane its running in. However, if you have it like this:

terminal -> asciinema rec -> tmux attach

asciinema sees all of it because its parent is your terminal, not tmux pane.